The invention relates to lubrication control device for use in power transmissions.
Lubrication distribution is an important consideration when designing an automobile transmission. Lubricant acts to cool friction-engaging devices such as clutches and brakes. For durability and wear performance, it is desirable to have a consistent, controlled flow of lubricant to the required device without delivering more than is needed, as this will siphon lubricant from other areas of the transmission requiring lubrication. Therefore it is desirable to position a device between two structures adjacent a lubrication flow path to control the flow of lubricant to a downstream lubricant-requiring mechanism. A controlled flow thrust bearing may control flow but it is not capable of accommodating varying assembly gaps. Thus it requires a set assembly gap. Therefore a lubrication control device which further accommodates and accounts for varying assembly gap tolerances in between the structures is desirable.
The present invention is for a lubrication control device usable in an automatic transmission to control the rate of lubrication flow between two housings of varying assembly gap and differential rotational speeds. The gap between the housings defines an annular flow path in which the lubrication control device is situated. The lubrication control device is a two-piece device including a washer and a belleville spring. The washer is in constant contact with the first housing and has one or more radial slots to permit a prescribed flow of lubricant through the annular flow path to the lubrication-requiring mechanism. The belleville spring operates to account for varying assembly gap differences between the housings. One end of the spring is in contact with the second housing and the other end is piloted by a seating on the washer, wherein the belleville spring provides a spring force to maintain contact between the washer and first housing. This ensures that there is no flow leakage around the lubrication control device. Instead a precise rate of lubricant flows through the radial slots to the lubricant-requiring mechanism.